Quantum dot carrier dynamics and far-infrared devices

Carrier dynamics in self-assembled quantum dots, grown by molecular beam epitaxy, have been studied. The temperature dependence of the relaxation times, measured by room temperature high frequency impedance response of quantum dot lasers and by low temperature (T=4K) differential transmission spectroscopy. strongly suggests that electronhole scattering is the dominant scattering mechanism in quantum dots. The favorable relaxation times can be exploited to realize far infrared emission and detection based on intersubband transitions in the dots.